Osr2 functions as a biomechanical checkpoint to aggravate CD8+ T cell exhaustion in tumor.

Alterations in extracellular matrix (ECM) architecture and stiffness represent hallmarks of cancer. Whether the biomechanical property of ECM impacts the functionality of tumor-reactive CD8+ T cells remains largely unknown. Here, we reveal that the transcription factor (TF) Osr2 integrates biomechanical signaling and facilitates the terminal exhaustion of tumor-reactive CD8+ T cells. Osr2 expression is selectively induced in the terminally exhausted tumor-specific CD8+ T cell subset by coupled T cell receptor (TCR) signaling and biomechanical stress mediated by the Piezo1/calcium/CREB axis. Consistently, depletion of Osr2 alleviates the exhaustion of tumor-specific CD8+ T cells or CAR-T cells, whereas forced Osr2 expression aggravates their exhaustion in solid tumor models. Mechanistically, Osr2 recruits HDAC3 to rewire the epigenetic program for suppressing cytotoxic gene expression and promoting CD8+ T cell exhaustion. Thus, our results unravel Osr2 functions as a biomechanical checkpoint to exacerbate CD8+ T cell exhaustion and could be targeted to potentiate cancer immunotherapy.

Gender differences in risk factors for ischemic stroke: a longitudinal cohort study in East China.

OBJECTIVES: Epidemiological studies of stroke and its risk factors can help develop strategies to prevent stroke. We aimed to explore the current gender-specific prevalence of stroke and associated risk factors. METHODS: Data were collected using a structured precoded questionnaire designed by the Stroke Screening and Prevention Programme of the National Health and Wellness Commission Stroke Prevention and Control Project Committee, between June 2020 and November 2021. A total of 7394 residents took part in the study, 187 of whom had a stroke. The baseline information of each participant was obtained and included in this study. The chi-square test and Kruskal-Wallis tests were used to examine the relationship between these indicators and stroke, and then multivariate logistic regression was used to construct the prediction scale between different genders. RESULTS: of 7394 participants,4571 (61.82%) were female. The overall prevalence of stroke patients in the study population was 2.53%, Multivariate analysis found that residence status (OR = 0.43, p = 0.002) 、HCY (OR = 0.962, p = 0.000)、Previous TIA (OR = 0.200, p = 0.002) 、Hypertension (OR = 0.33, p = 0.000) and Dyslipidemia (OR = 0.668, p = 0.028) were significant predictors of stroke. there are gender differences in the traditional risk factors for stroke, and women have more risk factors. ROC analysis confirmed the accuracy of the stroke risk model, and the AUC of the stroke risk model for the general population was 0.79 with p < 0.05. In the gender model, the female AUC was 0.796 (p < 0.05). and the male AUC was 0.786 with p < 0.05. CONCLUSION: The prevalence of stroke in adults aged 40 years and above is high in eastern China were high. management of risk factors can effectively prevent the occurrence of most strokes. more attention should be paid to gender differences associated with stroke.

Tailored Porous Ferrocene-Based Metal-Organic Frameworks as High-Performance Proton Conductors.

Although crystalline metal-organic frameworks (MOFs) have gained a great deal of interest in the field of proton conduction in recent years, the low stability and poor proton conductivity (σ) of some MOFs have hindered their future applications. As a result, resolving the issues listed above must be prioritized. Due to their exceptional structural stability, MOFs with ferrocene groups that exhibit particular physical and chemical properties have drawn a lot of attention. This study describes the effective preparation of a set of three-dimensional ferrocene-based MOFs, MIL-53-FcDC-Al/Ga and CAU-43, containing both main group metals and 1,1'-ferrocene dicarboxylic acid (H2FcDC). Multiple measurements, including powder X-ray diffraction (PXRD), infrared (IR), and scanning electron microscopy (SEM), confirmed that the addition of ferrocene groups enhanced the thermal, water, and acid-base stabilities of the three MOFs. Consequently, their proton-conductive behaviors were meticulously measured utilizing the AC impedance approach, and their best proton conductivities are 5.20 × 10-3, 2.31 × 10-3, and 1.72 × 10-4 S/cm at 100 °C/98% relative humidity (RH), respectively. Excitingly, MIL-53-FcDC-Al/Ga demonstrated an extraordinarily ultrahigh σ of above 10-4 S·cm-1 under 30 °C/98% RH. Using data from structural analysis, PXRD, SEM, thermogravimetry (TG), and activation energy, their proton transport mechanisms were thoroughly examined. The fact that these MOFs are notably easy to assemble, inexpensive, toxin-free, and stable will increase the range of practical uses for them.

Comparative Study on Proton Conductivity and Mechanism Analysis of Two Imidazole Modified Imine-Based Covalent Organic Frameworks.

This work elucidates the potential impact of intramolecular H-bonds within the pore walls of covalent organic frameworks (COFs) on proton conductivity. Employing DaTta and TaTta as representative hosts, it was observed that their innate proton conductivities (σ) are both unsatisfactory and σ(DaTta)<σ(TaTta). Intriguingly, the performance of both imidazole-loaded products, Im@DaTta and Im@TaTta is greatly improved, and the σ of Im@DaTta (0.91×10-2  S cm-1 ) even surpasses that of Im@TaTta (3.73×10-3  S cm-1 ) under 100 °C and 98 % relative humidity. The structural analysis, gas adsorption tests, and activation energy calculations forecast the influence of imidazole on the H-bonded system within the framework, leading to observed changes in proton conductivity. It is hypothesized that intramolecular H-bonds within the COF framework impede efficient proton transmission. Nevertheless, the inclusion of an imidazole group disrupts these intramolecular bonds, leading to the formation of an abundance of intermolecular H-bonds within the pore channels, thus contributing to a dramatic increase in proton conductivity. The related calculation of Density Functional Theory (DFT) provides further evidence for this inference.

Syntheses and High Proton Conductivities of Two 3D Zr(IV)/Hf(IV)-MOFs from Furandicarboxylic Acid.

With the gradual progress of research on proton-conducting metal-organic framework (MOFs), it has become a challenging task to find MOF materials that are easy to prepare and have low toxicity, high stability, and splendid proton conductivity. With the abovementioned objectives in mind, we selected the non-toxic organic ligand 2,5-furandicarboxylic acid and the low toxic quadrivalent metals zirconium(IV) or hafnium(IV) as starting materials and successfully obtained 2 three-dimensional porous MOFs, [M6O4(OH)4(FDC)4(OH)4(H2O)4] [M = ZrIV (1) and HfIV (2)], with ultrahigh water stability using a rapid and green synthesis approach. Their proton conductive ability is remarkable, thanks to the large number of Lewis acidic sites contained in their porous frameworks and the abundant H-bonding network, hydroxyl groups, as well as coordination and crystalline water molecules. The positive correlation of their proton conductivity with relative humidity (RH) and the temperature was observed. Notably, their optimized proton conductivities are 2.80 × 10-3 S·cm-1 of 1 and 3.38 × 10-3 S·cm-1 of 2 under 100 °C/98% RH, which are at the forefront of Zr(IV)/Hf(IV) MOFs with prominent proton conductivity. Logically, their framework features, nitrogen/water adsorption/desorption data, and activation energy values are integrated to deduce their proton conductivity and conducting mechanism differences.

Icing on the Cake: Imidazole-Anchored Strategy To Enhance the Proton Conductivity of Two Isostructural Ce(IV)/Hf(IV) Metal-Organic Frameworks.

In the field of proton conduction, the acquisition of crystalline metal-organic frameworks (MOFs) with high stability and ultrahigh proton conductivity has been of great research value and is worth continuous exploration. Here, we greenly synthesized a three-dimensional porous MOF (MOF-801-Ce) by using [(NH4)2Ce(NO3)6 and fumaric acid as starting materials and solvothermally synthesized Hf-UiO-66-NO2 by using HfCl4 and 2-nitroterephthalic acid as starting materials. A series of measurements have shown that both MOFs exhibit good water stability, acid-base stability, and thermal stability and demonstrate outstanding proton conductivity. At 100 °C and 98% relative humidity (RH), the proton conductivities (σ) could be 2.59 × 10-3 S·cm-1 for MOF-801-Ce and 0.89 × 10-3 S·cm-1 for Hf-UiO-66-NO2. To pursue higher proton conductivity, we further adopted the evaporation approach to encapsulate imidazole molecules in the pores of the two compounds, achieving the imidazole-encapsulated MOFs, Im@MOF-801-Ce and Im@Hf-UiO-66-NO2. As expected, their σ values were significantly boosted by almost an order of magnitude up to 10-2 S·cm-1. Finally, their proton-conductive mechanisms were explored in light of the structural information, gas adsorption/desorption, and other tests. The outstanding structural stability of these MOFs and their durability of the proton conduction capability manifested that they have great promise in electrochemical fields.

Two Dual-Function Zr/Hf-MOFs as High-Performance Proton Conductors and Amines Impedance Sensors.

In the field of sensing, finding high-performance amine molecular sensors has always been a challenging topic. Here, two highly stable 3D MOFs DUT-67(Hf) and DUT-67(Zr) with large specific surface areas and hierarchical pore structures were conveniently synthesized by solvothermal reaction of ZrCl4/HfCl4 with a simple organic ligand, 2,5-thiophene dicarboxylic acid (H2TDC) according to literature approach. By analyzing TGA data, it was found that the two MOFs have defects (unsaturated metal sites) that can interact with substrates (H2O and volatile amine gas), which is conducive to proton transfer and amine compound identification. Further experiments showed that at 100 °C and 98% relative humidity (RH), the optimized proton conductivities of DUT-67(Zr) and DUT-67(Hf) can reach the high values of 2.98 × 10-3 and 3.86 × 10-3 S cm-1, respectively. Moreover, the room temperature sensing characteristics of MOFs' to amine gases were evaluated at 68, 85 and 98% RHs, respectively. Impressively, the prepared MOFs-based sensors have the desired stability and higher sensitivity to amines. Under 68% RH, the detection limits of DUT-67(Zr) or DUT-67(Hf) for volatile amine gases were 0.5 (methylamine), 0.5 (dimethylamine) and 1 ppm (trimethylamine), and 0.5 (methylamine), 0.5 (dimethylamine) and 0.5 ppm (trimethylamine), respectively. As far as we know, this is the best performance of ammonia room temperature sensors in the past proton-conductive MOF sensors.

Clinical features and treatment outcomes of Castleman disease in children: a retrospective cohort in China.

Castleman disease (CD) is a rare lymphoproliferative disorder of undetermined etiology. Unicentric CD (UCD) and multicentric CD (MCD) are two phenotypes of CD diagnosed by the histopathology of lymph nodes. We attempted to describe a pediatric CD cohort to optimize the management of this disease. We reviewed the medical records of pediatric patients diagnosed with CD between April, 2004, and October, 2022, at the Children's Hospital of Fudan University. Prognosis information was collected in January, 2023, by telephone inquiry. Twenty-two patients with UCD and 2 patients with MCD were identified, all with hyaline vascular (HV) type. The median ages at diagnosis were 10.75 years (IQR 8, 12.81) for UCD and 14.42 years (IQR 13.42, 15.42) for MCD. The most common lesion location of UCD was the neck (9/22, 40.91%) and abdomen (9/22, 40.91%). Systematic symptoms occurred on 10/22 (45.45%) patients with UCD and 1/2 (50%) patients with MCD, and abnormal laboratory indexes were detected in both. Resection and biopsy were performed on all patients. One out of two patients with MCD also received rituximab for upfront therapy. After a median of 4 years (IQR 1.5, 6) of follow-up time, the overall survival was 100% and the complete remission rate in UCD was 63%. There was no relapse or progression. CONCLUSIONS: Our series demonstrated that HV-UCD was the most common type in children. Resection and biopsy were used for both deterministic diagnoses and treatments. Despite the high possibility to develop systematic inflammation, children with CD showed promising outcomes. WHAT IS KNOWN: • Castleman disease is a rare lymphoproliferative disorder with limited cohort studies, especially in pediatrics. • The ubiquity of delayed confirmations and misdiagnoses points to a lack of knowledge about etiology and characteristics, which is a prerequisite for novel therapeutics. WHAT IS NEW: • We retrospectively reviewed and analyzed the clinical and pathological symptoms, laboratory and imaging features, and treatment outcomes of a Chinese pediatric cohort with Castleman disease. • Our work may improve the recognition and optimize the management of this rare disease in children.

High Protonic Conductivity of Three Highly Stable Nanoscale Hafnium(IV) Metal-Organic Frameworks and Their Imidazole-Loaded Products.

Attracted by the exceptional structural rigidity and inherent porous structures of the Hf-based metal-organic frameworks (MOFs), we adopted a rapid synthesis approach to preparing three nanoscale MOFs, Hf-UiO-66 (1), Hf-UiO-66-(OH)2 (2), and Hf-UiO-66-NH2 (3), and systematically explored the water-assisted proton conductivities of the original ones and the post-modified products. Interestingly, the proton conductivities (σ) of all three MOFs exhibit significant temperature and humidity dependence. At 98% RH and 100 °C, their optimal σ values can reach up to 10-3 S·cm-1. Consequently, imidazole units are loaded into 1-3 to obtain related MOFs, Im@1, Im@2, and Im@3, and the σ values of the imidazole-loaded products are boosted to 10-2 S·cm-1. Note that these modifications not only do not change the frameworks of the pristine MOFs but also do not affect their high chemical and water stability. The proton-conductive mechanisms of these MOFs before and after modification have been thoroughly discussed based on structural analyses, N2 and H2O vapor adsorptions, and activation energy values. The excellent structural stability as well as the durability and stability of their proton conduction ability indicate that these MOFs can be used in the field of fuel cells and so on.

Comparative Studies on the Proton Conductivities of Hafnium-Based Metal-Organic Frameworks and Related Chitosan or Nafion Composite Membranes.

Hafnium (Hf)-based UiO-66 series metal-organic frameworks (MOFs) have been widely studied on gas storage, gas separation, reduction reaction, and other aspects since they were first prepared in 2012, but there are few studies on proton conductivity. In this work, one Hf-based MOF, Hf-UiO-66-fum showing UiO-66 structure, also known as MOF-801-Hf, was synthesized at room temperature using cheap fumaric acid as the bridging ligand, and then imidazole units were successfully introduced into MOF-801-Hf to obatin a doped product, Im@MOF-801-Hf. Note that both MOF-801-Hf and Im@MOF-801-Hf demonstrate excellent thermal, water, and acid-base stabilities. Expectedly, the maximum proton conductivity (σ) of Im@MOF-801-Hf (1.46 × 10-2 S·cm-1) is nearly 4 times greater than that of MOF-801-Hf (3.98 × 10-3 S·cm-1) under 100 °C and 98% relative humidity (RH). To explore their possible practical application value, we doped them into chitosan (CS) or Nafion membranes as fillers, namely, CS/MOF-801-Hf-X, CS/Im@MOF-801-Hf-Y, and Nafion/MOF-801-Hf-Z (X, Y, and Z are the doping percentages of MOF in the membrane, respectively). Intriguingly, it was found that CS/MOF-801-Hf-6 and CS/Im@MOF-801-Hf-4 indicated the highest σ values of 1.73 × 10-2 and 2.14 × 10-2 S·cm-1, respectively, under 100 °C and 98% RH and Nafion/MOF-801-Hf-9 also revealed a high σ value of 4.87 × 10-2 S·cm-1 under 80 °C and 98% RH, which showed varying degrees of enhancement compared to the original MOFs or pure CS and Nafion membranes. Our study illustrates that these Hf-based MOFs and related composite membranes offer great potential in electrochemical fields.

Structural Effect on Proton Conduction in Two Highly Stable Disubstituted Ferrocenyl Carboxylate Frameworks.

It is still a great challenge for people to obtain high proton conductive solid crystalline materials and accurately grasp their proton conduction mechanism. Herein, two highly stable disubstituted ferroceneyl carboxylate frameworks (DFCFs), {[HOOC(CH2)2OC]Fcc[CO(CH2)2COOH]} (DFCF 1) (Fcc = (η5-C5H4)Fe(η5-C5H4)) and [(HOOC)Fcc(COOH)] (DFCF 2) supported by intramolecular or intermolecular hydrogen bonds and π-π interactions were constructed and characterized by single crystal X-ray diffraction. Consequently, their water-assisted proton migration was researched systematically. As expected, 1 exhibited ultrahigh proton conductivity of 1.14 × 10-2 S·cm-1 at 373 K and 98% RH due to the presence of high-density free -COOH units. Unexpectedly, 2 displayed a low proton conductivity of 1.99 × 10-5 S·cm-1. On the basis of the analysis of crystal data, we believe that different arrangements of carboxyl groups lead to the different proton conductivity. Even more surprisingly, the proton conductivities of the two DFCFs are lower than those of their relevant monosubstituted ferroceneyl carboxylate frameworks (MFCFs), [FcCO(CH2)2COOH] (MFCF A) (Fc = (η5-C5H5)Fe(η5-C5H4)) (1.17 × 10-1 S·cm-1) and [FcCOOH] (MFCF B) (1.01 × 10-2 S·cm-1) under same conditions that were previously reported by us. This phenomenon indicates that the presence of a high number of free carboxyl groups in the framework does not necessarily cause high proton conductivity. We found that the arrangement of free carboxyl groups in the ferrocenyl framework plays a decisive role in proton conduction. This new discovery will provide guidance for the design of high proton conductive materials with free -COOH units.

Two Highly Stable Proton Conductive Cobalt(II)-Organic Frameworks as Impedance Sensors for Formic Acid.

Metal-organic frameworks (MOFs) have been extensively explored as advanced chemical sensors in recent years. However, there are few studies on MOFs as acidic gas sensors, especially proton conductive MOFs. In this work, two new proton-conducting 3D MOFs, {[Co3 (p-CPhHIDC)2 (4,4'-bipy)(H2 O)]⋅2 H2 O}n (1) (p-CPhH4 IDC=2-(4-carboxylphenyl)-1 H-imidazole-4,5-dicarboxylic acid; 4,4'-bipy=4,4'-bipyridine) and {[Co3 (p-CPhHIDC)2 (bpe)(H2 O)]⋅3 H2 O}n (2) (bpe=trans-1,2-bis(4-pyridyl)ethylene) have been solvothermally prepared and investigated their formic acid sensing properties. Both MOFs 1 and 2 show temperature- and humidity-dependent proton conductive properties and exhibit optimized proton conductivities of 1.04×10-3 and 7.02×10-4  S cm at 98 % relative humidity (RH) and 100 °C, respectively. The large number of uncoordinated carboxylic acid sites, free and coordination water molecules, and hydrogen-bonding networks inside the frameworks are favorable to the proton transfer. By measuring the impedance values after exposure to formic acid vapor at 98 % or 68 % RH and 25 °C, both MOFs indicate reproducibly high sensitivity to the analyte. The detection limit of formic acid vapor is as low as 35 ppm for 1 and 70 ppm for 2. Meanwhile, both MOFs also show commendable selectivity towards formic acid among interfering solutions. The proton conducting and formic acid sensing mechanisms have been suggested according to the structural analysis, Ea calculations, N2 and water vapor absorptions, PXRD and SEM measurements. This work will open a new avenue for proton-conductive MOF-based impedance sensors and promote the potential application of these MOFs for indirectly monitoring the concentrations of formic acid vapors.

Impressive Proton Conductivities of Two Highly Stable Metal-Organic Frameworks Constructed by Substituted Imidazoledicarboxylates.

There is great interest in the promising applications of proton-conductive metal-organic frameworks (MOFs) in the field of electrochemistry. Thus, seeking more types of MOFs with high proton conductivity is of great importance. Herein, we designed and prepared two substituted imidazoledicarboxylate-based MOFs, {[Cd( p-TIPhH2IDC)2]·H2O} n [1; p-TIPhH3IDC = 2- p-(1 H-1,2,4-triazolyl)phenyl-1 H-4,5-imidazoledicarboxylic acid] and [Sr(DMPhH2IDC)2] n [2; DMPhH3IDC = 2-(3,4-dimethylphenyl)-1 H-imidazole-4,5-dicarboxylic acid], and fully explored their water-assisted proton conduction. The best conductivity for 1 of 1.24 × 10-4 S·cm-1 is higher than that of most previous conductive Cd-MOFs under similar conditions. 2 has the highest conductivity (0.92 × 10-3 S·cm-1) among the reported conductive Sr-MOFs. Via structural analysis, Ea values, water vapor adsorptions, and powder X-ray diffraction and scanning electron microscopy tests, reasonable proton pathways and conduction mechanisms were highlighted. It should be emphasized that the N-heterocyclic units (imidazole and triazole) and carboxyl and hydrogen-bonding networks in the frameworks all play crucial roles in the transmission of proton conductivity. Our research offers more choice for the preparation of desired proton-conductive materials.

A Highly Stable Two-Dimensional Copper(II) Organic Framework for Proton Conduction and Ammonia Impedance Sensing.

This work reports the design and fabrication of a proton conductive 2D metal-organic framework (MOF), [Cu(p-IPhHIDC)]n (1) (p-IPhH3 IDC=2-(p-N-imidazol-1-yl)-phenyl-1 H-imidazole-4,5-dicarboxylic acid) as an advanced ammonia impedance sensor at room temperature and 68-98 % relative humidity (RH). MOF 1 shows the optimized proton conductivity value of 1.51×10-3  S cm-1 at 100 °C and 98 % RH. Its temperature-dependent and humidity-dependent proton conduction properties have been explored. The large amount of uncoordinated carboxylate groups between the layers plays a vital role in the resultant conductivity. Distinctly, the fabricated MOF-based sensor displays the required stability toward NH3 , enhanced sensitivity, and notable selectivity for NH3 gas. At room temperature and 68 % RH, it gives a remarkable gas response of 8620 % to 130 ppm NH3 gas and lower detection limit of 2 ppm towards NH3 gas. It is also found that the gas response of the ammonia sensor increases linearly with the increase of NH3 gas concentration under 68-98 % RH and room temperature. Moreover, the sensor indicates excellent reversibility and selectivity toward NH3 versus N2 , H2 , O2 , CO, CO2 , benzene, and MeOH. Based on structural analyses, activation energy calculations, water and NH3 vapor absorptions, and PXRD determinations, proton conduction and NH3 sensing mechanisms are suggested.

Enhancing Proton Conductivity of a 3D Metal-Organic Framework by Attaching Guest NH3 Molecules.

By reaction of a newly designed organic ligand, [3-(naphthalene-1-carbonyl)-thioureido] acetic acid (C10H7C(O)NHC(S)NHCH2COOH; H3L), with Cu(OAc)2, a metal-organic framework [(CuI4CuII4L4)·3H2O] n (1) containing unique mixed-valence [CuI4Cu4IIL4] subunits has been successfully synthesized and structurally characterized. MOF 1 displays a three-dimensional open framework bearing one-dimensional channels. Consequently, a new derivative MOF [CuI4CuII4L4] n-NH3 (2) is procured upon exposure of 1 to NH3 vapors from 28 wt % aqueous NH3 solution, which bears 2 NH3 and 4 H2O molecules in accordance with the elemental and thermal analyses. Both 1 and 2 exhibit relatively high water stability, whose proton conduction properties under water vapor have been researched. Notably, 2 shows an ultrahigh proton conductivity of 1.13 × 10-2 S cm-1, which is 2 orders of magnitude larger than that of MOF 1 (4.90 × 10-4 S cm-1) under 100 °C and 98% RH. On the basis of the structural data, Ea values, H2O and ammonia vapor absorptions, and PXRD measurements, the proton transfer mechanisms were suggested. This is an efficient and convenient way to obtain suitable and highly proton-conducting materials by attaching NH3 molecules.

A Water-Stable Proton-Conductive Barium(II)-Organic Framework for Ammonia Sensing at High Humidity.

In view of environmental protection and the need for early prediction of major diseases, it is necessary to accurately monitor the change of trace ammonia concentration in air or in exhaled breath. However, the adoption of proton-conductive metal-organic frameworks (MOFs) as smart sensors in this field is limited by a lack of ultrasensitive gas-detecting performance at high relative humidity (RH). Here, the pellet fabrication of a water-stable proton-conductive MOF, Ba( o-CbPhH2IDC)(H2O)4] n (1) ( o-CbPhH4IDC = 2-(2-carboxylphenyl)-1 H-imidazole-4,5-dicarboxylic acid) is reported. The MOF 1 displays enhanced sensitivity and selectivity to NH3 gas at high RHs (>85%) and 30 °C, and the sensing mechanism is suggested. The electrochemical impedance gas sensor fabricated by MOF 1 is a promising sensor for ammonia at mild temperature and high RHs.

Surfactant Binding to Polymer-Water Interfaces in Atomistic Simulations.

Attractive interactions between additive molecules and particle surfaces are key parameters in the design of waterborne suspensions and coatings. We use atomistic molecular dynamics (MD) simulations to determine the potential of mean force for a commonly used industrial surfactant sodium dodecyl sulfate (SDS) interacting with acrylate latex particles. We investigate how the potential of mean force and binding free energy depend on the amount of SDS adsorbed, solution ionic strength, and presence of other charged groups on the particle surface. We show that the potential of mean force for SDS is a sum of two independent terms, from the hydrophobic surfactant tail and charged headgroup: dragging the surfactant tail into solution contributes a linear potential of about kT per CH2 group, while the headgroup is repelled by like charges on the surface with a potential of about the zeta potential. Commercial acrylate latex particles also bear multivalent charged "hairs" as a remnant of their synthesis. These charged hairs result in a heterogeneously charged surface, for which SDS binds more or less strongly depending on the local environment.

Atomistic Molecular Dynamics Simulations of Charged Latex Particle Surfaces in Aqueous Solution.

Charged particles in aqueous suspension form an electrical double layer at their surfaces, which plays a key role in suspension properties. For example, binder particles in latex paint remain suspended in the can because of repulsive forces between overlapping double layers. Existing models of the double layer assume sharp interfaces bearing fixed uniform charge, and so cannot describe aqueous binder particle surfaces, which are soft and diffuse, and bear mobile charge from ionic surfactants as well as grafted multivalent oligomers. To treat this industrially important system, we use atomistic molecular dynamics simulations to investigate a structurally realistic model of commercial binder particle surfaces, informed by extensive characterization of particle synthesis and surface properties. We determine the interfacial profiles of polymer, water, bound and free ions, from which the charge density and electrostatic potential can be calculated. We extend the traditional definitions of the inner and outer Helmholtz planes to our diffuse interfaces. Beyond the Stern layer, the simulated electrostatic potential is well described by the Poisson-Boltzmann equation. The potential at the outer Helmholtz plane compares well to the experimental zeta potential. We compare particle surfaces bearing two types of charge groups, ionic surfactant and multivalent oligomers, with and without added salt. Although the bare charge density of a surface bearing multivalent oligomers is much higher than that of a surfactant-bearing surface at realistic coverage, greater counterion condensation leads to similar zeta potentials for the two systems.

Remarkable water-mediated proton conductivity of two porous zirconium(IV)/hafnium(IV) metal-organic frameworks bearing porphyrinlcarboxylate ligands.

Obtaining crystalline materials with high structural stability as well as super proton conductivity is a challenging task in the field of energy and material chemistry. Therefore, two highly stable metal-organic frameworks (MOFs) with macro-ring structures and carboxylate groups, Zr-TCPP (1) and Hf-TCPP (2) assembled from low-toxicity as well as highly coordination-capable Zr(IV)/Hf(IV) cations and the multifunctional linkage, meso-tetra(4-carboxyphenyl)porphine (TCPP) have attracted our strong interest. Note that TCPP as a large-size rigid ligand with high symmetry and multiple coordination sites contributes to the formation of the two stable MOFs. Moreover, the pores with large sizes in the two MOFs favor the entry of more guest water molecules and thus result in high H2O-assisted proton conductivity. First, their distinguished structural stabilities covering water, thermal and chemical stabilities were verified by various determination approaches. Second, the dependence of the proton conductivity of the two MOFs on temperature and relative humidity (RH) is explored in depth. Impressively, MOFs 1 and 2 demonstrated the optimal proton conductivities of 4.5 × 10-4 and 0.78 × 10-3 S·cm-1 at 100 °C/98 % RH, respectively. Logically, based on the structural information, gas adsorption/desorption features, and activation energy values, their proton conduction mechanism was deduced and highlighted.

Exploring antecedents and outcomes of burnout among emergency department staff using the job demands-resources model: A scoping review protocol.

INTRODUCTION: High levels of burnout are prevalent among Emergency Department staff due to chronic exposure to job stress. There is a lack of knowledge about anteceding factors and outcomes of burnout in this population. AIMS: To provide a comprehensive overview of burnout and identify its workplace antecedents and outcomes among Emergency Department staff. METHODS: The scoping study will follow the methodology outlined by the Joanna Briggs Institute. PubMed, Scopus, Web of Science, APA PsycInfo, and CINAHL databases will be searched using predefined strategies. Two reviewers will screen the title, abstract and full text separately based on the eligibility criteria. Data will be charted, coded, and narratively synthesized based on the job demands-resources model. CONCLUSION: The results will provide insights into the underlying work-related factors contributing to burnout and its implications for individuals, healthcare organizations, and patient care.